The conventional open wrench is disclosed in U.S. Pat. No. 3,023,654 and generally comprises a body having a head and a first recess is defined in the head. A stop is formed at the opening of the first recess which has a threaded portion, having inner threads, at the end portion of the first recess.
A slide is located in the second recess and has a contact portion which protrudes from the opening of the body. The contact portion has a sliding portion which is matched with the shaped of the first recess. The sliding portion has a rod at the lower end thereof.
A locking member is located in the first recess and has outer threads which are threadedly connected to the threaded portion of the first recess. A passage is defined through the locking member and the rod of the slide is inserted into the passage.
A resilient member is mounted to the rod of the slide and contacts between the sliding portion and the locking member to allow the slide movable in the first recess to perform as a ratchet wrench.
However, the slide, the resilient member, the locking member and the threaded portion in the body are necessary to allow the slide to be movable in the first recess. There are more than three parts required and the threaded portion has to be made by extra work. The inner diameter of the first recess is small and the threads are different to be manufactured. The manufacturing cost is high.
The slide in the first recess is biased by the resilient member and is prevented from dropping from the first recess by the stop at the opening of the first recess. The position where the stop is set is difficult to be decided. The stop has to be set at the position where the contact portion of the slide is exposed beyond the opening and located adjacent to the object to be tightened or loosened. If the stop is located deep inside of the first recess, the contact portion cannot contact the object which is not able to be rotated effectively. If the stop is located at too shallow in the first recess, the contact portion protrudes too much from the opening so that the object has to push the contact portion backward.
When the stop has a smaller portion protruding from the opening, and the manufacturers need to cut a portion of the stop and this work is difficult. Generally, the maximum thickness that can be cut is 0.5 mm and this requires precise machining skill. If the whole wrench is deemed as a defective product, the lost of expense is too high.
The present invention intends to provide an open wrench with a slide to perform as a ratchet wrench and the present invention improve the shortcomings of the conventional wrenches.